oven opening construction

[james]

i think you are going to need the angle iron. i wish i would have taken a picture when i did mine. it's a little tricky. i have posted a sketch of how i did it at <http://www.cpsusa.com/ebay/angleiron2.jpg>www.cpsusa.com/ebay/angleiron2.jpg (as viewed from the top).*

you need two pieces of iron. an angle iron and a flat piece of iron (i got mine at home depot).*i cannot imagine how to cut the angle irons without an angle grinder. (maybe someone else has some suggestions re: cutting the iron).**

i completed*the row around the dome except in the area next to the angle iron. the angle iron is about the same height as the row of bricks laid next to it and serves as a brick substitute. the angle iron was placed like a pup tent. you then take a brick and place it on top of the angle iron and the flat iron and then sort of move the angle iron and the flat iron back and forth (towards and away from the center of the oven) until your eyeball tells you that the bricks to be laid on top of the irons will line up at roughly the same height as the bricks on the next row. (try to match the interior top of the bricks, not the bottoms). you then slather mortar all around the angle iron to hold it steady and go have a beer.*

you then come back and begin laying bricks on top and find that you really don't have it lined up too good and then redo it several times. by the fourth beer its starting to look pretty good. for piece of mind i cut a keystone brick to fit as the middle brick in the bricks laid on top of the angle iron because (1) the bricks kept slipping off the angle iron and (2) i needed the arch support given by the keystone to hold them all in place. the rows got a little ugly above the angle iron but by using a little more mortar here and a little less there i was able to even things out withinin a couple of courses.

hope that helps...

bob





----- Original Message -----
From: <mailto:marirose@mindspring.com>kanznenbaumberg
To: <mailto:fornobravo@yahoogroups.com>fornobravo@yaho ogroups.com
Sent: Thursday, October 28, 2004 7:10 AM
Subject: [fornobravo] Problem building a dome


Hi,
I've got a problem... I can't figure out how to place the dome's
firebricks above the opening. I made the opening without a metal
angle. The opening is an arch. Please help.
Stanley

[Yahoo-Archive]

Typically, angle iron is used to support the door opening. But, you
shouldn't have a real problem doing it without steel. In fact I'm of 2
minds about the steel myself -- on one hand, it doesn't suffer any
degradation like mortar might and thus gives me some insurance that
it'll stay there. On the other hand not sure about the long term
effect of the smoke on that steel and I know the steel moves
differently than the brick does so you don't want to encase the steel
in mortar.

Making the opening an arch is actually the key to success without
steel I think. A flat opening would be more difficult. In your case,
just make a form of plywood & 2x4s in the shape & size you want. Cut
out 2 plywood sides and screw in 2x4 spacers so the thickness of the
form is sufficient to support your bricks. Then you lay the rings just
as if you had brick under them. With an arch you're making a compound
curve (curving in the plane of the oven while arching) so some extra
cutting with your saw/grinder/chisel may be needed but should result
in a nice looking (and performing) door opening.

[Yahoo-Archive]

Hi Stanley,

I agree with Jim on the point of building an arched opening, its not easy but can be achieved with a little patience. One of the problems you will be encountering is the visibility of the arch and your perception that it will not stand up. The depth (length of the bricks) of the arched opening at the bottom of the arch is considerably less than when you get to the top of the arch (because the dome is receding in diameter). Hence, one believes that it won?t stand up and I will not be able to build it. All you have to do is construct an arch form as Jim suggested, now for the fun bit, cut some pieces of wood to the same dimensions as your firebricks / half firebricks. Then use these as templates to determine the type / angle, and, so forth of cut that you require for the arch bricks to meet and marry up with the dome bricks. Transfer your template to a firebrick and cut, belive me it will work, and don?t get hung up on the fact that you may have large mortar joints. Yep, it would be better if the joints were as small as possible, however, I have seen many old ovens still in use that have wide mortar joints and don?t look like they are about to fall down.

Alf

[Yahoo-Archive]

Well... You are right! That could be a solution.*
But yesterday I got tired thinking about it, knocked down the arch and went ahead with a 1/4 steel*angle.*
We hope to finish the dome today and start putting up a chimney.
Thanks,
Stanley